Owing to their ability to be relatively easily formulated, manufactured, handled and stored, tablets and capsules are the oral administration means of choice for a majority of drug products. Troches, syrups, suspensions, and gums are alternative administration means to tablets or capsules. Although drugs are generally more easily ingested via these alternative administration means by users having difficulty swallowing tablets or capsules, such compositions are generally unable to provide the delayed release properties obtainable with tablet and capsule formulations. Further, despite the use of flavoring additives, the above described alternative administration means are oftentimes unable to mask the bitter or otherwise objectionable taste or aftertaste of many medicaments. Additionally, suspensions and syrups are prone to problems such as sedimentation and/or crystallization.
Emulsified systems represent a class of oral administration means which have been effectively used to mask objectionable tasting medicaments. Currently marketed emulsions include oil-in-water type systems formulated as vitamin supplements and laxatives. Oil-in-water type systems tend to break down at relatively rapid rates following ingestion and are generally unsuitable for those applications wherein the delayed release of a pharmaceutically active ingredient is required. Further, the utility of such state of the art emulsions has been limited by their tendency to separate, with the passage of time, into distinct oil and water phases.
It is an object of this invention to provide an easily ingestible drug administration means having delayed release properties. It is a further object of this invention to provide an oral administration means capable of masking bitter or objectionable testing medicaments. It is yet another object of this invention to provide a physically stable oral administration means.